OTTAWA - The word "environment" was suddenly deleted from a federal government website that described Conservative proposals to change the law protecting Canada's navigable waterways.

The Navigable Waters Protection Act is being altered as part of the government's latest omnibus budget bill.

The proposed changes would make the Act apply to fewer bodies of water than before, in a bid to make the system more efficient.

The opposition parties say the move will further weaken environmental protection — and they say the proof is on the web.

The NDP pointed out on Tuesday that the government's own "Frequently Asked Questions" about the Act posted on the Internet stated that the changes reflected the government's "ongoing concern towards maintaining the safety of public navigation and the environment."

It also referred to companies potentially constructing "dangerous works in navigable waters."

But by Wednesday, that section of the Transport Canada website had been altered to remove the reference to the environment and the dangerous works. NDP Leader Tom Mulcair called the deletion "Orwellian."

"It's Orwellian, they made their website disappear. ... They want to make the environment disappear. We're going to stand up and protect the environment," Mulcair said during a House of Commons speech on the omnibus budget bill, C-45.

Transport Minister Denis Lebel said the original content on the website was a mistake.

"The Transport Canada website always specified that the Navigable Waters Protection Act was designed to protect navigation rights for all Canadians. That has not changed," said Lebel.

"The department reviewed the website and the erroneous information was pulled from the web."